Propylene polymer catalyst donor component

ABSTRACT

A solid, hydrocarbon-insoluble, catalyst component useful in polymerizing olefins containing magnesium, titanium, and halogen further contains an internal electron donor comprising a compound containing electron donating substituents with a structure: 
     
       
         
         
             
             
         
       
         
         
           
             wherein D 1  and D 2  are selected individually from 
           
         
       
    
     
       
         
         
             
             
         
       
         
         
           
             and R, R 2 , R 3 , R 4 , R 5 , R 6 , and R 7  individually are hydrocarbon or substituted hydrocarbon groups containing 1 to 20 carbon atoms and R 2 , R 3 , R 4 , R 6 , and R 7  may be hydrogen; R 4  may be —NR 2 ; and 
             wherein groups R 1  and R 2 , R 2  and R 3 , R 3  and R 4 , R 3  and R 5 , and groups R 6  and R 7  may be joined to form a cyclic structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/659,713 filed Mar. 8, 2005, which is incorporated by referenceherein.

FIELD OF THE INVENTION

This invention relates to components useful in propylene polymerizationcatalysts, and particularly relates to electron donor components used incombination with magnesium-containing supported titanium-containingcatalyst components.

BACKGROUND OF THE INVENTION

Use of solid, transition metal-based, olefin polymerization catalystcomponents is well known in the art including such solid componentssupported on a metal oxide, halide or other salt such aswidely-described magnesium-containing, titanium halide-based catalystcomponents. Such catalyst components are referred to as “supported.”Although many polymerization and copolymerization processes and catalystsystems have been described for polymerizing or copolymerizingalpha-olefins, it is advantageous to tailor a process and catalystsystem to obtain a specific set of properties of a resulting polymer orcopolymer product. For example, in certain applications, a combinationof acceptably high activity, good morphology, desired particle sizedistribution, acceptable bulk density, and the like are requiredtogether with polymer characteristics such as stereospecificity,molecular weight distribution, and the like.

Typically, supported catalyst components useful for polymerizingpropylene and higher alpha-olefins as well as for polymerizing propyleneand higher olefins with minor amounts of ethylene and otheralpha-olefins contain an electron donor component as an internalmodifier. Such internal modifier is an integral part of the solidsupported component and is distinguished from an external electron donorcomponent, which together with an aluminum alkyl component, comprisesthe catalyst system. Typically, the external modifier and aluminum alkylare combined with the solid supported component shortly before thecombination is contacted with an olefin monomer or in the presence ofolefin monomer.

Selection of the internal modifier can affect catalyst performance andthe resulting polymer formed from a catalyst system. Generally, organicelectron donors have been described as useful in preparation of thestereospecific supported catalyst components including organic compoundscontaining oxygen, nitrogen, sulfur, and/or phosphorus. Such compoundsinclude organic acids, organic acid anhydrides, organic acid esters,alcohols, ethers, aldehydes, ketones, amines, amine oxides, amides,thiols, various phosphorus acid esters and amides, and the like.Mixtures of organic electron donors have been described as useful inincorporating into supported catalyst components. Examples of organicelectron donors include dicarboxy esters such as alkyl phthalate andsuccinate esters.

In current practice, alkyl phthalate esters are commonly used as anelectron donor internal modifier in commercial propylene polymerizationcatalyst systems. However, certain environmental questions have beenraised concerning continued use of phthalate derivatives in humancontact applications.

Numerous individual processes or process steps have been disclosed toproduce improved supported, magnesium-containing, titanium-containing,electron donor-containing olefin polymerization or copolymerizationcatalysts. For example, Arzoumanidis et al., U.S. Pat. No. 4,866,022,incorporated by reference herein, discloses a method for forming anadvantageous alpha-olefin polymerization or copolymerization catalyst orcatalyst component which involves a specific sequence of specificindividual process steps such that the resulting catalyst or catalystcomponent has exceptionally high activity and stereospecificity combinedwith very good morphology. A solid hydrocarbon-insoluble, alpha-olefinpolymerization or copolymerization catalyst or catalyst component withsuperior activity, stereospecificity and morphology characteristics isdisclosed as comprising the product formed by 1) forming a solution of amagnesium-containing species from a magnesium hydrocarbyl carbonate ormagnesium carboxylate; 2) precipitating solid particles from suchmagnesium-containing solution by treatment with a transition metalhalide and an organosilane; 3) reprecipitating such solid particles froma mixture containing a cyclic ether; and 4) treating the reprecipitatedparticles with a transition metal compound and an electron donor.

Arzoumanidis et al., U.S. Pat. No. 4,540,679, incorporated by referenceherein, discloses a process for the preparation of a magnesiumhydrocarbyl carbonate by reacting a suspension of a magnesium alcoholatein an alcohol with carbon dioxide and reacting the magnesium hydrocarbylcarbonate with a transition metal component.

Arzoumanidis et al., U.S. Pat. No. 4,612,299, incorporated by referenceherein, discloses a process for the preparation of a magnesiumcarboxylate by reacting a solution of a hydrocarbyl magnesium compoundwith carbon dioxide to precipitate a magnesium carboxylate and reactingthe magnesium carboxylate with a transition metal component.

Particular uses of propylene polymers depend upon the physicalproperties of the polymer, such as molecular weight, viscosity,stiffness, flexural modulus, and polydispersity index (molecular weightdistribution (M_(w)/M_(n))). In addition, polymer or copolymermorphology often is critical and typically depends upon catalystmorphology. Good polymer morphology generally involves uniformity ofparticle size and shape, resistance to attrition and an acceptably highbulk density. Minimization of very small particles (fines) typically isimportant especially in gas-phase polymerizations or copolymerizationsin order to avoid transfer or recycle line pluggage.

The invention described relates to use of an internal modifier in apropylene polymerization catalyst component, which does not contain aphthalate derivative.

SUMMARY OF THE INVENTION

A solid, hydrocarbon-insoluble, catalyst component useful inpolymerizing olefins containing magnesium, titanium, and halogen furthercontains an internal electron donor comprising a compound containingelectron donating substituents with a structure:

wherein D¹ and D² are selected individually from

and R, R², R³, R⁴, R⁵, R⁶, and R⁷ individually are hydrocarbon orsubstituted hydrocarbon groups containing 1 to 20 carbon atoms and R²,R³, R⁴, R⁶, and R⁷ may be hydrogen; R⁴ may be —NR₂; and

wherein groups R² and R³, R³ and R⁴, R³ and R⁵, and groups R⁶ and R⁷ maybe joined to form a cyclic structure.

DESCRIPTION OF THE INVENTION

Supported catalyst components of this invention contain at least oneinternal electron donor comprising a derivative containing electrondonating substituents with a structure:

wherein D¹ and D² are selected individually from

and R, R², R³, R⁴, R⁵, R⁶, and R⁷ individually are hydrocarbon orsubstituted hydrocarbon groups containing 1 to 20 carbon atoms and R²,R³, R⁴, R⁶, and R⁷ may be hydrogen; R⁴ may be —NR₂; and

wherein groups R¹ and R², R² and R³, R³ and R⁴, R³ and R⁵, and groups R⁶and R⁷ may be joined to form a cyclic structure.

In one aspect of this invention, typical electron donor compounds ofthis invention are alkyl esters of a derivative illustrated above, inwhich donor group D² is an alkyl carboxylic acid ester. For thisinvention, alkyl groups include cycloalkyl groups such as cyclohexyl.Such alkyls typically contain at least two and preferably at least threecarbon atoms. Suitable alkyls also may contain up to 12 and, typically,up to 8 carbon atoms. Other suitable alkyls contain from 4 to 6 carbonatoms. Typical examples of alkyl esters useful in this invention includeethyl, propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl,isopentyl, hexyl, 2-ethylhexyl, cyclohexyl, cyclopentyl, and octylesters. Especially suitable alkyls are isopropyl, n-butyl, s-butyl, andt-butyl. In this aspect of the invention, donor group D¹ typically is anacyl, carboxylic acid ester, or oxy group as illustrated above. Typicalacyl groups (R⁴CO—) include alkyl, alkylaryl, arylalkyl, andaryl-substituted acyl groups. C₁-C₂₀ alkyl substituted acyl groups arepreferred, with C₂-C₈ alkyl most preferred. A typical example of asuitable arylalkyl group is benzyl. Typical oxy groups (R⁵O—) includealkyloxy, alkylaryloxy, arylalkyloxy, and aryloxy groups in which R⁵contains 1 to 20 carbon atoms with 2 to 8 carbon atoms preferred.

In other embodiments of this invention, hydrocarbyl substituents (R² andR³) also include alkyl, alkylaryl, arylalkyl, and aryl-substituted acylgroups containing 1 to 20 carbon atoms with 1 to 8 carbon atomspreferred. Alkyl groups (R² and R³) may be joined to form cyclicstructures with 4 to 7 (preferably 5 to 6) atom cyclic structurespreferred.

In another embodiment of this invention, substituents R⁶ and R⁷ maycontain 1 to 20 carbon atoms with 1 to 8 carbon atoms preferred andalkyl substituents may be joined to form cyclic structures with 4 to 7(preferably 5 to 6) atom cyclic structures preferred.

In another embodiment of this invention, substituents R³ and R⁵ maycontain 1 to 20 carbon atoms with 1 to 8 carbon atoms preferred andalkyl substituents may be joined to form cyclic structures with 4 to 7(preferably 5 to 6) atom cyclic structures preferred.

Cyclic structures also may contain heteroatoms such as nitrogen and/oroxygen and may contain internal unsaturation.

Although, the alkyl groups forming alkyl dicarboxylic acid esters ofthis invention may be the same, the invention includes alkyldicarboxylic acid esters having different alkyl groups.

In more detail, preferably, R and R⁵ are not hydrogen and typically R⁴is not hydrogen, and R⁴ also may be —NR₂.

Alkyl groups used in this invention also may be substituted withcompatible groups containing heteroatoms including nitrogen, phosphorus,silicon, and halogens. Thus, a hydrocarbon group used in this inventionmay be substituted with an amine, amide, chloro, bromo, or silyl group.Cyclic structures which may be incorporated into donor compounds maycontain hetero atoms, such as nitrogen, silicon, and phosphorus.

Representative examples of donor compounds of this invention includederivatives of phenylacetoxyacetates (D²=alkyl carboxylic ester groupand R¹=phenyl(Ph)) such as an alkyl ethyl phenylacetoxyacetate.Typically, the alkyl group (R) contains 1 to 8 carbon atoms andpreferably includes ethyl, propyl, isopropyl, n-butyl, isobutyl, ands-butyl. The donor substituent D¹ in these structures includes“t-butoxycarbonyl” or the t-butyl ester of a carboxylic acid group(R=t-butyl), which sometimes is represented as “Boc” or “BOC” instructural formulas. Other donor compounds of this invention withsimilar structures include D¹ substituents wherein the carboxylic acidester derivative preferably has R contain 1 to 10 carbon atoms andincludes alkyl having 1 to 8 carbon atoms and arylalkyl groups typicallycontaining at least about 7 and may contain up to about 20, preferablyup to 15, carbon atoms such as benzyl (“Bn”) or a substituted benzylgroup.

In many aspects, the donor compounds of this invention are described asderivatives of alpha hydroxy carboxylic acids.

Examples of structures (with hydrogens not shown) included in thisinvention include:

In another aspect of this invention, the donor compound may be describedas

wherein R, R², and R³ are as defined previously and R′ is defined as R,but may be a different group within such structure. Thus, R may be ethyland R′ may be t-butyl.

Similarly, another structure defining a donor compound of this inventionis

wherein R, R², and R³ are as defined previously.

Mixtures of donor compounds described in this invention may be used aswell as mixtures of these donor compounds with other donor compoundsknown in the art.

High activity supported (HAC) titanium-containing components useful inthis invention generally are supported on hydrocarbon-insoluble,magnesium-containing compounds in combination with an electron donorcompound. Such supported titanium-containing olefin polymerizationcatalyst component typically is formed by reacting a titanium (IV)halide, an organic electron donor compound and a magnesium-containingcompound. Optionally, such supported titanium-containing reactionproduct may be further treated or modified by further chemical treatmentwith additional electron donor or Lewis acid species.

Suitable magnesium-containing compounds include magnesium halides; areaction product of a magnesium halide such as magnesium chloride ormagnesium bromide with an organic compound, such as an alcohol or anorganic acid ester, or with an organometallic compound of metals ofGroups I-III; magnesium alcoholates; or magnesium alkyls.

Examples of supported catalysts are prepared by reacting a magnesiumchloride, alkoxy magnesium chloride or aryloxy magnesium chloride with atitanium halide, such as titanium tetrachloride, and furtherincorporation of an electron donor compound. In a preferablepreparation, the magnesium-containing compound is dissolved, or is in aslurry, in a compatible liquid medium, such as a hydrocarbon to producesuitable catalyst component particles.

The possible solid catalyst components listed above only areillustrative of many possible solid, magnesium-containing, titaniumhalide-based, hydrocarbon-insoluble catalyst components useful in thisinvention and known to the art. This invention is not limited to aspecific supported catalyst component.

In a typical supported catalyst of this invention, the magnesium totitanium atom ratio typically is above about 0.5 to 1 and may range toabout 20 to 1. Greater amounts of magnesium may be employed withoutadversely affecting catalyst component performance, but typically thereis no need to exceed a magnesium to titanium ratio of about 20:1. Morepreferably, the magnesium to titanium ratio ranges from about 2:1 toabout 15:1. The internal electron donor components typically areincorporated into the solid, supported catalyst component in a totalamount ranging up to about 1 mole per gram atom of titanium in thetitanium compound, and preferably from about 0.001 to about 0.6 mole pergram atom of titanium in the titanium compound. Typical amounts ofinternal donor are at least 0.01 mole per gram atom of titanium,preferably above about 0.05 and typically above about 0.1 mole per gramatom of titanium. Also, typically, the amount of internal donor is lessthan 1 mole per gram atom of titanium, and preferably below about 0.5,and more preferably below about 0.3 mole per gram atom of titanium.

Supported catalyst components known to the art may be used with theinternal donors described in this invention. Typically, the internalelectron donor material of this invention is incorporated into a solid,supported catalyst component during formation of such component.Typically, such electron donor material is added with, or in a separatestep, during treatment of a solid magnesium-containing material with atitanium (IV) compound. Most typically, a solution of titaniumtetrachloride and the internal electron donor modifier material iscontacted with a magnesium-containing material. Suchmagnesium-containing material typically is in the form of discreteparticles and may contain other materials such as transition metals andorganic compounds. Also, a mixture of magnesium chloride, titaniumtetrachloride and the internal donor may be formed into an activecatalyst component by ball-milling.

The preferred solid, hydrocarbon-insoluble catalyst or catalystcomponent of this invention for the stereoregular polymerization orcopolymerization of alpha-olefins comprises the product formed by aprocess, which comprises a first step of forming a solution of amagnesium-containing species in a liquid wherein themagnesium-containing species is formed by reacting amagnesium-containing compound with carbon dioxide or sulfur dioxide. Themagnesium-containing compound from which the magnesium-containingspecies is formed is a magnesium alcoholate, a magnesium hydrocarbylalcoholate, or a hydrocarbyl magnesium compound. When carbon dioxide isused, the magnesium-containing species is a hydrocarbyl carbonate or acarboxylate. When sulfur dioxide is employed, the resultingmagnesium-containing species is a hydrocarbyl sulfite (ROSO₂ ⁻) or anhydrocarbyl sulfinate (RSO₂ ⁻). Preferable catalyst components areprepared in a manner similar to those described in U.S. Pat. No.4,946,816, incorporated by reference herein.

Generally, magnesium hydrocarbyl carbonate is prepared by reactingcarbon dioxide with a magnesium alcoholate. For example, magnesiumhydrocarbyl carbonate is formed by suspending magnesium ethoxide inethanol and adding carbon dioxide until the magnesium ethoxide dissolvesforming magnesium ethyl carbonate. If, however, the magnesium ethoxidewere suspended in 2-ethylhexanol, magnesium 2-ethylhexyl carbonate,magnesium ethyl carbonate and magnesium ethyl/2-ethylhexyl carbonate maybe formed. If the magnesium ethoxide is suspended in a liquidhydrocarbon or halohydrocarbon which is free of alcohol, the addition ofcarbon dioxide results in the breaking apart of the magnesium ethoxideparticles and the magnesium hydrocarbyl carbonate reaction product doesnot dissolve. The reaction of a magnesium alcoholate with carbon dioxidecan be represented as:

wherein n is a whole number or fraction up to 2, and wherein R is ahydrocarbyl group of 1 to 20 carbon atoms. In addition, a magnesiumalcoholate-containing two different aforesaid hydrocarbyl groups may beemployed. From the standpoint of cost and availability, magnesiumalcoholates which are preferred for use according to this invention arethose of the formula Mg(OR)₂ wherein R is as defined below. In terms ofcatalytic activity and stereospecificity, best results are achievedthrough the use of magnesium alcoholates of the formula Mg(OR′)₂ whereinR′ is an alkyl radical of 1 to about 8 carbon atoms, an aryl radical of6 to about 12 carbon atoms or an alkaryl or aralkyl radical of 7 toabout 12 carbon atoms. Magnesium ethoxide is most preferred.

Specific examples of magnesium alcoholates that are useful according tothis invention include: Mg(OCH₃)₂, Mg(OC₂H₅)₂, Mg(OC₄H₉)₂, Mg(OC₆H₅)₂,Mg(OC₆H₁₃)₂, Mg(OC₉H₁₉)₂, Mg(OC₁₀H₇)₂, Mg(OC₁₂H₉)₂, Mg(OC₁₂H₂₅)₂,Mg(OC₁₆H₃₃)₂, Mg(OC₁₈H₃₇)₂, Mg(OC₂₀H₄₁)₂, Mg(OCH₃)(OC₂H₅),Mg(OCH₃)(OC₆H₁₃), Mg(OC₂H₅)(OC₈H₁₇), Mg(OC₆H₁₃)(OC₂₀H₄₁),Mg(OC₃H₇)(OC₁₀H₇), Mg(OC₂H₄Cl)₂ and Mg(OC₁₆H₃₃)(OC₁₈H₃₇). Mixtures ofmagnesium alcoholates also may be used if desired.

A suitable magnesium hydrocarbyl alcoholate has the formula MgR(OR′)wherein R and R′ are as defined hereinabove for the magnesiumalcoholate. When alcohol is used as the suspending medium for thereaction between the magnesium hydrocarbyl alcoholate and carbon dioxideor sulfur dioxide, the magnesium hydrocarbyl alcoholate is a functionalequivalent of the magnesium alcoholate because the magnesium hydrocarbylalcoholate is converted to the magnesium alcoholate in alcohol. However,when the suspending medium does not contain alcohol, the magnesiumhydrocarbyl alcoholate reacts with carbon dioxide as:

wherein y+x=n≧2 and y=0 for x=n≦1.0.In the case of

is the resulting magnesium-containing species.

When the magnesium compound from which the magnesium-containing speciesis formed is a hydrocarbyl magnesium compound having the formula XMgR,where X is a halogen and R is a hydrocarbyl group of 1 to 20 carbonatoms, the reaction of the hydrocarbyl magnesium compound with carbondioxide forms a magnesium carboxylate and can be represented as follows:

If the hydrocarbyl magnesium compound contains two hydrocarbyl groups,the reaction is represented as:

where R is as defined for X—MgR.

The hydrocarbyl magnesium compounds useful in this invention have thestructure R—Mg-Q wherein Q is hydrogen, halogen or R′ (each R′ isindependently a hydrocarbyl group of 1 to 20 carbon atoms.) Specificexamples of hydrocarbyl magnesium compounds useful in this inventioninclude: Mg(CH₃)₂, Mg(C₂H₅)₂, Mg(C₄H₉)₂, Mg(C₆H₅)₂, Mg(C₆H₁₃)₂,Mg(C₉H₁₉)₂, Mg(C₁₀H₇)₂, Mg(C₁₂H₉)₂, Mg(C₁₂H₂₅)₂, Mg(C₁₆H₃₃)₂,Mg(C₂₀H₄₁)₂, Mg(CH₃)(C₂H₅), Mg(CH₃)(C₆H₁₃), Mg(C₂H₅)(C₈H₁₇),Mg(C₆H₁₃)(C₂₀H₄₁), Mg(C₃H₇)(C₁₀H₇), Mg(C₂H₄Cl)₂ and Mg(C₁₆H₃₃)(C₁₈H₃₇),Mg(C₂H₅)(H), Mg(C₂H₅)(Cl), Mg(C₂H₅)(Br), etc. Mixtures of hydrocarbylmagnesium compounds also can be employed if desired. From the standpointof cost and availability, dihydrocarbyl magnesium compounds preferredfor use in this invention are those of the formula MgR₂ wherein R is asdefined above. In terms of catalytic activity and stereospecificity,best results are achieved through the use of hydrocarbyl magnesiumhalide compounds of the formula MgR′Q′ wherein R′ is an alkyl radical of1 to about 18 carbon atoms, an aryl radical of 6 to about 12 carbonatoms or an alkaryl or aralkyl radical of 7 to about 12 carbon atoms andQ′ is chloride or bromide.

Most preferably, the magnesium-containing compound is a magnesiumalcoholate, and the resulting magnesium-containing species is amagnesium hydrocarbyl carbonate.

For example, a magnesium alcoholate may be used which is prepared byreacting magnesium metal turnings to completion with a lower molecularweight alcohol, such as methanol, ethanol, or 1-propanol, with orwithout a catalyst such as iodine or carbon tetrachloride, to form asolid magnesium alcoholate. Any excess alcohol is removed by filtration,evaporation or decantation. Use as the magnesium-containing compound ofa magnesium alcoholate produced in this manner affords a solution of themagnesium-containing species which has a substantially reducedviscosity.

Diluents or solvents suitable for use in the carbonation of themagnesium compounds to form the magnesium-containing species includealcohols containing from 1 to 12 carbon atoms, non-polar hydrocarbonsand halogenated derivatives thereof, ethers and mixtures thereof thatare substantially inert to the reactants employed and, preferably, areliquid at the temperatures of use. It also is contemplated to conductthe reaction at elevated pressure so that lower-boiling solvents anddiluents can be used even at higher temperatures. Examples of usefulsolvents and diluents include alcohols such as methanol, ethanol, 1- or2-propanol, t-butyl alcohol, benzyl alcohol, the amyl alcohols,2-ethylhexanol and branched alcohols containing 9 or 10 carbon atoms;alkanes such as hexane, cyclohexane, ethylcyclohexane, heptane, octane,nonane, decane, undecane, and the like; haloalkanes such as1,1,2-trichloroethane, carbon tetrachloride, and the like; aromaticssuch as toluene, xylenes and ethylbenzene; and halogenated andhydrogenated aromatics such as chlorobenzene, o-dichlorobenzene,tetrahydronaphthalene and decahydronaphthalene.

The solution of the magnesium-containing species typically comprises atleast one monohydroxy alcohol containing from 2 to about 18 carbonatoms, preferably at a ratio of the total number of moles of the atleast one alcohol to the number of moles of the aforesaidmagnesium-containing compound in the range of from about 1.45:1, morepreferably from about 1.6:1, to about 2.3:1, more preferably to about2.1:1. Alcohols that are suitable for use in the present inventioninclude those having the structure HOR wherein R is an alkyl radical of1 to about 18 carbon atoms, an aryl radical of 6 to about 12 carbonatoms or an alkaryl or aralkyl radical of 7 to about 12 carbon atoms.Typically, one or more alcohols containing from 1 to 12 carbon atoms canbe used, such as ethanol, 1- or 2-propanol, t-butyl alcohol,cyclohexanol, 2-ethylhexanol, amyl alcohols including isoamyl alcohol,and branched alcohols having 9 to 12 carbon atoms. Preferably,2-ethylhexanol or ethanol is employed.

In somewhat greater detail, the magnesium-containing species is preparedby dissolving or suspending the magnesium-containing compound in aliquid. Approximately 10 to 80 parts by weight of themagnesium-containing compound is employed per 100 parts by weightliquid. A sufficient amount of carbon dioxide is bubbled into the liquidsuspension to provide from about 0.1 to 4 moles of carbon dioxide permole of the magnesium compound with mild stirring. Typically,approximately 0.3 to 4 moles of CO₂ are added to the solution orsuspension of the magnesium-containing compound with stirring at atemperature of about 0 to 100° C. over a period of approximately 10minutes to 24 hours.

Irrespective of which of the aforesaid magnesium-containing compounds isused to form the magnesium-containing species, solid particles areprecipitated from the aforesaid solution of the magnesium-containingspecies by treatment with a transition metal or Group IV halide andpreferably additionally with a morphology controlling agent. Thetransition metal or Group IV halide preferably is a titanium (IV) orsilicon halide and more preferably is titanium tetrachloride. While anyconvenient conventional morphology controlling agent can be employed,organosilanes are particularly suitable for use as the morphologycontrolling agent. Suitable organosilanes for this purpose include thosehaving a formula: R_(n)SiR′_(4-n), wherein n=0 to 4 and wherein R ishydrogen or an alkyl, alkoxy, haloalkyl or aryl radical containing oneto about ten carbon atoms, or a halosilyl radical or haloalkylsilylradical containing one to about eight carbon atoms, and R′ is OR or ahalogen. Typically, R is an alkyl or chloroalkyl radical containing oneto about eight carbon atoms and one to about four chlorine atoms, and R′is chlorine or an —OR radical containing one to four carbon atoms. Asuitable organosilane may contain different R′ groups. Mixtures oforganosilanes may be used. Preferable organosilanes includetri-methylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane,methyltrichlorosilane, tetraethoxysilane, tetrachlorosilane, andhexamethyldisiloxane. Typically, one or more alcohols containing from 1to 12 carbon atoms may be added, such as ethanol, 1- or 2-propanol,t-butyl alcohol, cyclohexanol, 2-ethylhexanol, amyl alcohols includingisoamyl alcohol, and branched alcohols having 9 to 12 carbon atoms.Preferably, 2-ethylhexanol or ethanol is employed.

Broadly, in accordance with this invention, the precipitated particlesare treated with a transition metal compound and an electron donor.Suitable transition metal compounds which can be used for this purposeinclude, compounds represented by the formula T_(a)Y_(b)X_(c-b) whereinT_(a) is a transition metal selected from Groups IV-B, V-B and VI-B ofthe Periodic Table of Elements, Y is oxygen, OR′ or NR′₂; wherein eachR′ is independently hydrogen or hydrocarbyl group of 1 to 20 carbonatoms; X is halogen, preferably chlorine or bromine; c has a valuecorresponding to the valence of the transition metal, T_(a); b has avalue of from 0 to 5 with a value of c-b being from at least 1 up to thevalue of the valence state of the transition metal T_(a). Suitabletransition metal compounds include halide compounds of titanium,zirconium, vanadium and chromium, such as chromyl chloride, vanadiumoxytrichloride, zirconium tetrachloride, vanadium tetrachloride, and thelike.

In addition to supported catalyst components formed from magnesiumalcoholates or magnesium hydrocarbyl carbonates as described above,other magnesium-containing supported components may be produced byreacting titanium halide-containing compounds with magnesium halides,such as magnesium chloride, magnesium oxyhalides, magnesium alkoxides,and the like. In preparation of suitable supported catalysts useful forolefin polymerization, an electron donor material is added duringformation of such component in which a magnesium compound is reactedwith a titanium halide-containing compound as described in the art.Irrespective of the method of formation, the supported catalystcomponents of this invention include the internal electron donormaterial described in this invention.

Titanium (IV) compounds useful in preparation of the catalyst orcatalyst component of this invention are titanium halides andhaloalcoholates having 1 to about 20 carbon atoms per alcoholate groupsuch as methoxy, ethoxy, butoxy, hexoxy, phenoxy, decoxy, naphthoxy,dodecoxy and eicosoxy. Mixtures of titanium compounds can be employed ifdesired. Preferred titanium compounds are the halides andhaloalcoholates having 1 to 8 carbon atoms per alcoholate group.Examples of such compounds include TiCl₄, TiBr₄, Ti(OCH₃)Cl₃,Ti(OC₂H₅)Cl₃, Ti(OC₄H₉)Cl₃, Ti(OC₆H₅)Cl₃, Ti(OC₆H₁₃)Br₃, Ti(OC₈H₁₇)Cl₃,Ti(OCH₃)₂Br₂, Ti(OC₂H₅)₂Cl₂, Ti(OC₆H₁₃)₂Cl₂, Ti(OC₈H₁₇)₂Br₂,Ti(OCH₃)₃Br, Ti(OC₂H₅)₃Cl, Ti(OC₄H₉)₃Cl, Ti(OC₆H₁₃)₃Br, andTi(OC₈H₁₇)₃Cl. Titanium tetrahalides and particularly TiCl₄ are mostpreferred from the standpoint of attaining maximum activity andstereospecificity.

The particles formed as described above, the titanium halide component,and the electron donor components described in this invention arereacted at temperatures ranging from about −10° C. to about 170° C.,generally over a period of several minutes to several hours.

Preferably, the aforesaid electron donor compounds and titanium compoundis contacted with the precipitated solid particles in the presence of aninert hydrocarbon or halogenated diluent, although other suitabletechniques can be employed. Suitable diluents are substantially inert tothe components employed and are liquid at the temperature and pressureemployed.

Preferably, although optional, the precipitated particles arereprecipitated from a solution containing, typically, a cyclic ether,and then the reprecipitated particles are treated with a transitionmetal compound and an electron donor as described above

In a typical reprecipitation procedure, the precipitated particles areentirely solubilized in a cyclic ether solvent and then particles areallowed to reprecipitate to form particles of uniform size. Thepreferable ether is tetrahydrofuran, although other suitable cyclicethers, such as tetrahydropyran and 2-methyltetrahydrofuran, may beused, which can solubilize the particles. Also, thioethers such astetrahydrothiophene can be used. In some instances, such as the use of2,2,5,5-tetrahydrofuran and tetrahydropyran-2-methanol, reprecipitationoccurs upon heating to about 55°-85° C. Other compounds may be usedwhich act in an equivalent manner, i.e., materials which can solubilizethe particles formed in Step B and from which solid uniform particlescan be reprecipitated, such as cyclohexene oxide, cyclohexanone, ethylacetate and phenyl acetate. Mixtures of such suitable materials may alsobe used.

A suitable diluent that can be used in any of the aforesaid steps shouldbe substantially inert to the reactants employed and preferably isliquid at the temperatures and pressures used. A particular step may beconducted at an elevated pressure so that lower boiling diluents can beused at higher temperatures. Typical suitable diluents are aromatic orsubstituted aromatic liquids, although other hydrocarbon-based liquidsmay be used. Aromatic hydrocarbons, such as toluene, and substitutedaromatics are useful. An especially suitable diluent is a halogenatedaromatic such as chlorobenzene or a mixture of a halogenated aromaticsuch as chlorobenzene and a halogenated aliphatic such asdichloroethane. Also useful are higher boiling aliphatic liquids such askerosene. Mixtures of diluents may be used. One useful diluent componentis Isopar G® which is a C₁₀-average isoparaffinic hydrocarbon boiling at156-176° C. Other examples of useful diluents include alkanes such ashexane, cyclohexane, methylcyclohexane, heptane, octane, nonane, decane,undecane, and the like; haloalkanes such as 1,2-dichloroethane,1,1,2-trichloroethane, carbon tetrachloride and the like; aromatics suchas benzene, toluene, xylenes and ethylbenzene; and halogenated andhydrogenated aromatics such as chlorobenzene and o-di-chlorobenzene.

Each of the aforesaid preparative steps is conducted in the substantialabsence of water, oxygen, carbon monoxide, and other extraneousmaterials capable of adversely affecting the performance of the catalystor catalyst component of this invention. Such materials are convenientlyexcluded by carrying out the procedures in the presence of an inert gassuch as nitrogen or argon, or by other suitable means. Optionally, allor part of the process can be conducted in the presence of one or morealpha-olefins which, when introduced into the preparative system ingaseous form, can serve to exclude catalyst poisons. The presence of oneor more alpha-olefins also can result in improved stereospecificity.Useful alpha-olefins include ethylene, propylene, butene-1,pentene-1,4-methylpentene-1, hexene-1, and mixtures thereof. Of course,any alpha-olefin employed should be of relatively high purity, forexample, polymerization grade or higher. Other precautions which aid inexcluding extraneous poisons include purification of any diluent to beemployed, such as by percolation through molecular sieves and/or silicagel prior to use, and drying and/or purifying other reagents.

As a result of the above-described preparation steps, there is obtaineda solid reaction product suitable for use as a catalyst or catalystcomponent. Prior to such use, it is desirable to removeincompletely-reacted starting materials from the solid reaction product.This is conveniently accomplished by washing the solid, after separationfrom any preparative diluent, with a suitable solvent, such as a liquidhydrocarbon or chlorocarbon, preferably within a short time aftercompletion of the preparative reaction because prolonged contact betweenthe catalyst component and unreacted starting materials may adverselyaffect catalyst component performance.

The final solid reaction product prepared may be contacted one or moretimes with at least one Lewis acid prior to polymerization. Such Lewisacids useful according to this invention are materials which are liquidor soluble in a liquid diluent at treatment temperatures and have Lewisacidity high enough to remove impurities such as unreacted startingmaterials and poorly affixed compounds from the surface of the solidreaction product. Preferred Lewis acids include halides of Group III-Vmetals which are in the liquid state at temperatures up to about 170° C.Specific examples of such materials include BCl₃, AlBr₃, TiCl₄, TiBr₄,SiCl₄, GeCl₄, SnCl₄, PCl₃ and SbCl₅. Preferable Lewis acids are TiCl₄and SiCl₄. Mixtures of Lewis acids can be employed if desired. SuchLewis acid may be used in a compatible diluent.

Although not required, the final solid reaction product may be washedwith an inert liquid hydrocarbon or halogenated hydrocarbon beforecontact with a Lewis acid. If such a wash is conducted, it is preferredto substantially remove the inert liquid prior to contacting the washedsolid with Lewis acid.

In an advantageous procedure, the magnesium chloride-based particles aretreated with titanium tetrachloride and then with titanium tetrachloridein the presence of the mixture of electron donors one or more times.More preferably, the product is treated one or more times with a liquidaromatic hydrocarbon such as toluene and finally with titaniumtetrachloride again. Such treatments are performed at elevatedtemperatures, typically from 75 to 135° C. at normal or slightlyelevated pressures from 1 to 3 bar for three to six times. Typicalindividual treatment times may vary from several minutes to severalhours, usually from 0.25 to 3 hours.

In an embodiment of this invention, a mixture of electron donors isincorporated into the supported catalyst component comprising a firstelectron donor and an additional electron donor. The first electrondonor is selected from the group of electron donors described above asrepresenting the class of electron donors of this invention. The secondelectron donor is a dialkylphthalate wherein each alkyl group may be thesame or different and contains from 3 to 5 carbon atoms. The additionalelectron donor is preferably a dibutylphthalate and more preferably isdi-n-butylphthalate or di-1-butylphthalate. The mole ratio of theadditional electron donor to the first electron donor may range fromabout 0.1:1 to about 20:1, preferably from about 0.3:1 to about 1:1.

Also, the internal electron donor material useful in this invention maybe combined with additional electron donors such as a polyhydrocarbylphosphonate, phosphinate, phosphate or phosphine oxide or an alkylaralkylphthalate, wherein the alkyl moiety contains from 2 to 10,preferably 3 to 6, carbon atoms and the aralkyl moiety contains from 7to 10, preferably to 8, carbon atoms, or an alkyl ester of an aromaticmonocarboxylic acid wherein the monocarboxylic acid moiety contains from6 to 8 carbon atoms and the alkyl moiety contains from 1 to 3 carbonatoms.

Useful polyhydrocarbyl phosphonates, phosphinates, phosphates, orphosphine oxides include:

wherein each hydrocarbyl group (R₁, R₂, and R₃) may be the same ordifferent and may be alkyl or aryl, and each contains from 1 to 12carbon atoms

Preferably each hydrocarbyl group (R₁, R₂ and R₃) is an alkyl group.Preferably a phosphonate is employed. Particular phosphonates that aresuitable for use as an aforesaid preferable component include dimethylmethylphosphonate, diethyl ethylphosphonate, diisopropylmethylphosphonate, dibutylbutylphosphonate, and di(2-ethylhexyl)2-ethylhexyl phosphonate.

The additional component also may be a dialkylphthalate wherein eachalkyl moiety may be the same or different and each contains at least 6carbon atoms, preferably up to 10 atoms. Particular dialkylphthalateswhich are suitable for use as an additional electron donor includedihexylphthalate and dioctylphthalate.

Also, the additional component may be an alkyl ester of an aliphaticmonocarboxylic acid wherein carboxylic acid moiety contains 2 to 20,preferably 3 to 6, carbon atoms and the alkyl moiety contains from 1 to3 carbon atoms. Particular alkyl esters that are suitable for use as theaforesaid first electron donor include methyl valerate, ethyl pivalate,methyl pivalate, methyl butyrate, and ethyl propionate.

In another alternative, the additional component may be adicycloaliphatic ester of an aromatic dicarboxylic acid wherein eachcycloaliphatic moiety may be the same or different and each containsfrom 5 to 7 carbon atoms, and preferably contains 6 carbon atoms.Preferably the ester is a dicycloaliphatic diester of an ortho aromaticdicarboxylic acid. Particular dicycloaliphatic esters that are suitablefor use as the aforesaid first electron donor includedicyclopentylphthalate, dicyclohexylphthalate, anddi-(methylcyclopentyl)-phthalate.

The additional component may be an alkyl aralkyl phthalate wherein thealkyl moiety contains 2 to 10, preferably 3 to 6, carbon atoms, and thearalkyl moiety contains from 7 carbon atoms up to 10, preferably up to8, carbon atoms. Particularly, alkyl aralkyl phthalates suitable for useas an additional component include benzyl n-butyl phthalate and benzyli-butyl phthalate. In another alternative, such additional componentalso may be an alkyl ester of an aromatic monocarboxylic acid whereinthe monocarboxylic acid moiety contains from 6 to 8 carbon atoms and thealkyl moiety contains from 1 to 3 carbon atoms. Particular alkyl estersthat are suitable for use as an additional component include methyltoluate, ethyl toluate, methyl benzoate, ethyl benzoate and propylbenzoate.

The mole ratio of first electron donor component described in thisinvention to the additional component is in the range of from about0.5:1, preferably from about 1:1, to about 3:1, preferably to about2.5:1. The mole ratio of the aforesaid second electron donor to thecombination of the first electron donor and the additional electrondonor ranges from about 4:1, preferably from about 7:1, to about 15:1,preferably to about 9:1.

Although the chemical structure of the catalyst or catalyst componentsof this invention is not known precisely, the components generallycomprise from about 1 to about 6 weight percent titanium, from about 10to about 25 weight percent magnesium, and from about 45 to about 65weight percent halogen. Preferably, the catalyst component of thisinvention comprise from about 2.0 to about 4 weight percent titanium,from about 15 to about 21 weight percent magnesium and from about 55 toabout 65 weight percent chlorine.

In the solid catalyst component of this invention produced by the methodof this invention, the atomic ratio of magnesium to titanium is at leastabout 0.3:1 and preferably, is from about 0.4:1 to about 20:1 and morepreferably, from about 3:1 to about 9:1.

Prepolymerization or encapsulation of the catalyst or catalyst componentof this invention also may be carried out prior to being used in thepolymerization or copolymerization of alpha olefins. A particularlyuseful prepolymerization procedure is described in U.S. Pat. No.4,579,836, which is incorporated herein by reference.

Typically, the catalyst or catalyst component of this invention is usedin conjunction with a cocatalyst component including a Group II or IIImetal alkyl and, typically, one or more modifier compounds. Useful GroupII and IIIA metal alkyls are compounds of the formula MR_(m) wherein Mis a Group II or IIIA metal, each R is independently an alkyl radical of1 to about 20 carbon atoms, and m corresponds to the valence of M.Examples of useful metals, M, include magnesium, calcium, zinc, cadmium,aluminum, and gallium. Examples of suitable alkyl radicals, R, includemethyl, ethyl, butyl, hexyl, decyl, tetradecyl, and eicosyl. From thestandpoint of catalyst component performance, preferred Group II andIIIA metal alkyls are those of magnesium, zinc, and aluminum wherein thealkyl radicals contain 1 to about 12 carbon atoms. Specific examples ofsuch compounds include Mg(CH₃)₂, Mg(C₂H₅)₂, Mg(C₂H₅)(C₄H₉), Mg(C₄H₉)₂,Mg(C₆H₁₃)₂, Mg(C₁₂H₂₅)₂, Zn(CH₃)₂, Zn(C₂H₅)₂, Zn(C₄H₉)₂, Zn(C₄H₉)(C₈H₁₇), Zn(C₆H₁₃)₂, Zn(C₆H₁₃)₃, and Al(C₁₂H₂₅)₃. A magnesium, zinc, oraluminum alkyl containing 1 to about 6 carbon atoms per alkyl radicalmay be used. Aluminum alkyls are preferred and most preferablytrialkylaluminums containing 1 to about 6 carbon atoms per alkylradical, and particularly triethylaluminum and triisobutylaluminum or acombination thereof are used.

If desired, metal alkyls having one or more halogen or hydride groupscan be employed, such as ethylaluminum dichloride, diethylaluminumchloride, and the like.

A typical catalyst system for the polymerization or copolymerization ofalpha olefins is formed by combining the supported titanium-containingcatalyst or catalyst component of this invention and an alkyl aluminumcompound as a co-catalyst, together with at least one external modifierwhich typically is an electron donor and, preferably, is a silane.Typically, useful aluminum-to-titanium atomic ratios in such catalystsystems are about 10 to about 500 and preferably about 30 to about 300.Typical aluminum-to-electron donor molar ratios in such catalyst systemsare about 2 to about 60. Typical aluminum-to-silane compound molarratios in such catalyst systems are about 3 to about 50.

To optimize the activity and stereospecificity of this cocatalystsystem, it is preferred to employ one or more external modifiers,typically electron donors, and including compounds such as silanes,mineral acids, organometallic chalcogenide derivatives of hydrogensulfide, organic acids, organic acid esters and mixtures thereof.

Organic electron donors useful as external modifiers for the aforesaidcocatalyst system are organic compounds containing oxygen, silicon,nitrogen, sulfur, and/or phosphorus. Such compounds include organicacids, organic acid anhydrides, organic acid esters, alcohols, ethers,aldehydes, ketones, silanes, amines, amine oxides, amides, thiols,various phosphorus acid esters and amides, and the like. Mixtures oforganic electron donors also may be used.

Particular organic acids and esters are benzoic acid, halobenzoic acids,phthalic acid, isophthalic acid, terephthalic acid, and the alkyl estersthereof wherein the alkyl group contains 1 to 6 carbon atoms such asmethyl chlorobenzoates, butyl benzoate, isobutyl benzoate, methylanisate, ethyl anisate, methyl p-toluate, hexylbenzoate, and cyclohexylbenzoate, and diisobutyl-phthalate as these give good results in termsof activity and stereospecificity and are convenient to use.

The aforesaid cocatalyst system advantageously and preferably containsan aliphatic or aromatic silane external modifier. Preferable silanesuseful in the aforesaid cocatalyst system include alkyl-, aryl-, and/oralkoxy-substituted silanes containing hydrocarbon moieties with 1 toabout 20 carbon atoms. Especially preferred are silanes having aformula: SiY₄, wherein each Y group is the same or different and is analkyl or alkoxy group containing 1 to about 20 carbon atoms. Preferredsilanes include isobutyltrimethoxysilane, diisobutyldimethoxysilane,diisopropyldimethoxysilane, n-propyltriethoxysilane,isobutylmethyldimethoxysilane, isobutylisopropyledimethoxysilane,dicyclopentyldimethoxysilane, tetraethylorthosilicate,dicyclohexyldimethoxysilane, diphenyldimethoxysilane,di-t-butyldimethoxysilane, and t-butyltrimethoxysilane.

In one aspect of this invention the substituted cycloalkanedicarboxylates identified above as catalyst component internal donorsmay be used as external donors alone or in combination with othersuitable external donors including the above-identified silanecompounds.

The catalyst or catalyst component of this invention is useful in thestereospecific polymerization or copolymerization of alpha-olefinscontaining 3 or more carbon atoms such as propylene, butene-1,pentene-1,4-methylpentene-1, and hexene-1, as well as mixtures thereofand mixtures thereof with ethylene. The catalyst or catalyst componentof this invention is particularly effective in the stereospecificpolymerization or copolymerization of propylene or mixtures thereof withup to about 30 mole percent ethylene or a higher alpha-olefin. Accordingto the invention, highly crystalline polyalpha-olefin homopolymers orcopolymers are prepared by contacting at least one alpha-olefin with theabove-described catalyst or catalyst component of this invention underpolymerization or copolymerization conditions. Such conditions includepolymerization or copolymerization temperature and time, pressure(s) ofthe monomer(s), avoidance of contamination of catalyst, choice ofpolymerization or copolymerization medium in slurry processes, the useof additives to control homopolymer or copolymer molecular weights, andother conditions well known to persons skilled in the art. Slurry-,bulk-, and vapor-phase polymerization or copolymerization processes arecontemplated herein.

The amount of the catalyst or catalyst component of this invention to beused varies depending on choice of polymerization or copolymerizationtechnique, reactor size, monomer to be polymerized or copolymerized, andother factors known to persons of skill in the art, and can bedetermined on the basis of the examples appearing hereinafter.Typically, a catalyst or catalyst component of this invention is used inamounts ranging from about 0.2 to 0.02 milligrams of catalyst to gram ofpolymer or copolymer produced.

Irrespective of the polymerization or copolymerization process employed,polymerization or copolymerization should be carried out at temperaturessufficiently high to ensure reasonable polymerization orcopolymerization rates and avoid unduly long reactor residence times,but not so high as to result in the production of unreasonably highlevels of stereorandom products due to excessively rapid polymerizationor copolymerization rates. Generally, temperatures range from about 0°to about 120° C. with a range of from about 20° C. to about 95° C. beingpreferred from the standpoint of attaining good catalyst performance andhigh production rates. More preferably, polymerization according to thisinvention is carried out at temperatures ranging from about 50° C. toabout 80° C.

Olefin polymerization or copolymerization according to this invention iscarried out at monomer pressures of about atmospheric or above.Generally, monomer pressures range from about 20 to about 600 psi (140to 4100 kPa), although in vapor phase polymerizations orcopolymerizations, monomer pressures should not be below the vaporpressure at the polymerization or copolymerization temperature of thealpha-olefin to be polymerized or copolymerized.

The polymerization or copolymerization time will generally range fromabout ½ to several hours in batch processes with corresponding averageresidence times in continuous processes. Polymerization orcopolymerization times ranging from about 1 to about 4 hours are typicalin autoclave-type reactions. In slurry processes, the polymerization orcopolymerization time can be regulated as desired. Polymerization orcopolymerization times ranging from about ½ to several hours aregenerally sufficient in continuous slurry processes.

Diluents suitable for use in slurry polymerization or copolymerizationprocesses include alkanes and cycloalkanes such as pentane, hexane,heptane, n-octane, isooctane, cyclohexane, and methylcyclohexane;alkylaromatics such as toluene, xylene, ethylbenzene, isopropylbenzene,ethyl toluene, n-propyl-benzene, diethylbenzenes, and mono- anddialkylnaphthalenes; halogenated and hydrogenated aromatics such aschlorobenzene. Chloronaphthalene, ortho-dichlorobenzene,tetrahydro-naphthalene, decahydronaphthalene; high molecular weightliquid paraffins or mixtures thereof, and other well-known diluents. Itoften is desirable to purify the polymerization or copolymerizationmedium prior to use, such as by distillation, percolation throughmolecular sieves, contacting with a compound such as an alkylaluminumcompound capable of removing trace impurities, or by other suitablemeans.

Examples of gas-phase polymerization or copolymerization processes inwhich the catalyst or catalyst component of this invention is usefulinclude both stirred bed reactors and fluidized bed reactor systems andare described in U.S. Pat. Nos. 3,957,448; 3,965,083; 3,971,786;3,970,611; 4,129,701; 4,101,289; 3,652,527; and 4,003,712, allincorporated by reference herein. Typical gas phase olefinpolymerization or copolymerization reactor systems comprise at least onereactor vessel to which olefin monomer and catalyst components can beadded and which contain an agitated bed of forming polymer particles.Typically, catalyst components are added together or separately throughone or more valve-controlled ports in the single or first reactorvessel. Olefin monomer, typically, is provided to the reactor through arecycle gas system in which unreacted monomer removed as off-gas andfresh feed monomer are mixed and injected into the reactor vessel. Forproduction of impact copolymers, homopolymer formed from the firstmonomer in the first reactor is reacted with the second monomer in thesecond reactor. A quench liquid, which can be liquid monomer, can beadded to polymerizing or copolymerizing olefin through the recycle gassystem in order to control temperature.

Irrespective of polymerization or copolymerization technique,polymerization or copolymerization is carried out under conditions thatexclude oxygen, water, and other materials that act as catalyst poisons.Also, according to this invention, polymerization or copolymerizationcan be carried out in the presence of additives to control polymer orcopolymer molecular weights. Hydrogen is typically employed for thispurpose in a manner well known to persons of skill in the art. Althoughnot usually required, upon completion of polymerization orcopolymerization, or when it is desired to terminate polymerization orcopolymerization or at least temporarily deactivate the catalyst orcatalyst component of this invention, the catalyst can be contacted withwater, alcohols, acetone, or other suitable catalyst deactivators in amanner known to persons of skill in the art.

The products produced in accordance with the process of this inventionare normally solid, predominantly isotactic polyalpha-olefins.Homopolymer or copolymer yields are sufficiently high relative to theamount of catalyst employed so that useful products can be obtainedwithout separation of catalyst residues. Further, levels of stereorandomby-products are sufficiently low so that useful products can be obtainedwithout separation thereof. The polymeric or copolymeric productsproduced in the presence of the invented catalyst can be fabricated intouseful articles by extrusion, injection molding, and other commontechniques.

The polymer component of the composition of this invention primarilycontains a high crystalline polymer of propylene. Polymers of propylenehaving substantial polypropylene crystallinity content now arewell-known in the art. It has long been recognized that crystallinepropylene polymers, described as “isotactic” polypropylene, containcrystalline domains interspersed with some non-crystalline domains.Noncrystallinity can be due to defects in the regular isotactic polymerchain which prevent perfect polymer crystal formation. The extent ofpolypropylene stereoregularity in a polymer can be measured bywell-known techniques such as isotactic index, crystalline meltingtemperature, flexural modulus, and, recently by determining the relativepercent of meso pentads (% m4) by carbon-13 nuclear magnetic resonance(¹³C NMR).

The propylene polymer especially useful in this invention has both ahigh nmr tacticity and a broadened molecular weight distribution (“MWD”)as measured by the ration of the weight average to number averagemolecular weights (M_(w)/M_(n)). Such molecular weights typically aremeasured by gel permeation chromatography (GPC) techniques known in theart. In addition, preferable polymers of this invention have flexuralmoduli above about 1800 MPa and typically above about 2100 MPa. Inaddition the nmr pentad tacticity typically is above 90% and preferablyis above about 95% and may be above about 97%. Typical polymer melt flowrates are 1 to 20 g/10 min.

A method to determine stereoregularity of a propylene polymer uses ¹³CNMR and is based on the ability to identify relative positions ofadjacent methyl groups on a polypropylene polymer backbone. If themethyl groups of two adjacent propylene monomer units (—CH(CH₃)—CH₂—)are on the same side of the polymer chain, such two methyl groups form ameso (“m”) dyad. The relative percentage of these meso dyads isexpressed as % m. If the two methyl groups of adjacent monomer units areon opposite sides of the polymer chain, such two methyl groups form aracemic (“r”) dyad, and the relative percentage of these racemic dyadsis expressed as % r. Advances in ¹³C NMR techniques permit measurementof the relative positioning of three, four, and five successive methylgroups, which are referred to as triads, tetrads and pentads,respectively.

Current NMR instruments can quantify the specific distribution ofpentads in a polymer sample. There are ten unique pentads which arepossible in a propylene polymer:

mmmm rrrr mmmr mmrm mmrr mrrm rmmr rmrm rmrr mrrr

A ball and stick representation of the mmmm pentad is:

Two of the possible pentads cannot be separated by NMR (mmrm and rmmr)and are reported together. Two of the ten pentads (mmrr and mrrm) resultfrom the displacement of a single methyl group on the opposite side ofthe polymer chain in an isotactic sequence. Since the mmmm (m4) pentadrepresents a perfect isotactic stereoregular structure, measurement ofthis pentad (as % m4) reflects isotacticity and potential crystallinity.As used herein, the term NMR tacticity index is the percent of m4 (% m4)pentads as measured by ¹³C NMR. Thus, if 96% of pentads measured by ¹³CNMR in a propylene polymer are m4, the NMR tacticity index is 96.

The invention described herein is illustrated, but not limited, by thefollowing examples.

EXAMPLES

A series of supported catalyst components are prepared using variousinternal electron donors. Examples using electron donors of thisinvention are described below, together with Comparative Runs not usingsuch internal electron donors.

Preparation of Donor Compounds

Preparation of donor modifier compounds are described below and in Table1.

Ethyl(phenylacetoxy)acetate (M1) was obtained from Aldrich Chemical Co

TABLE 1 Structures of modifier derivatives used in Table 2. NameStructure Ethyl (phenylacetoxy)- acetate M1

Di-n- butylphthalate M2

Catalyst PreparationsSynthesis of Magnesium Chloride-THF Catalyst Support

A magnesium chloride-THF adduct catalyst support was prepared in amanner similar to that described in U.S. Pat. No. 4,946,816 by reactinga solution of one equivalent of magnesium ethoxide in a toluene solutioncontaining 2-ethyl-1-hexanol with rapid agitation under 300 kPa ofcarbon dioxide at 93° C. for three hours under a blanket of dry nitrogenand contained approximately 0.1 gram equivalents of magnesium ethoxideper milliliter. The resulting magnesium hydrocarbyl carbonate solutionwas isolated and reacted with titanium tetrachloride (TiCl₄) (0.9equivalents) in toluene and the solid particles precipitated. After themixture containing the precipitate was stirred rapidly at about 25° C.for 15 minutes, magnesium hydrocarbyl carbonate solution was added tothe reactor through a bomb and thereafter solid particles precipitated.

After the mixture containing the precipitate was stirred for fiveadditional minutes, 0.25 equivalents of tetrahydrofuran (THF) were addedrapidly. The rapid stirring was continued and the temperature wasincreased to 60° C. within 15 minutes. The first formed solid dissolvedin the THF solution. Within about 5 minutes after the THF addition, asolid began to reprecipitate from solution. Stirring continued for 1hour at 60° C. after which agitation was stopped and the resulting solidwas allowed to settle. Supernatant was decanted and the solid washedwith portions of toluene.

Synthesis of Catalysts.

Catalyst Preparation Procedure A:

Catalyst A1: A magnesium chloride-THF adduct catalyst support asdescribed above (22.5 g) was suspended in 200 mL of heptane andtransferred under nitrogen to a 1-liter jacketed glass reactor fittedwith an overhead stirrer. The heptane was removed by decantation, thesolids washed with toluene, which then was decanted. More of toluene wasadded, and titanium tetrachloride (TiCl₄) (105 mL, Akzo) was added withstirring. The reactor contents were warmed to 90° C. and mixed for anadditional one hour. The alpha-hydroxy acid derivative donor modifier(M1) (2 mL) was added to the mixture by syringe, and the resultingmixture was stirred at 90° C. for one hour, and the solids were allowedto settle and supernatant decanted. Toluene and titanium tetrachloride(105 mL) were added and stirred at 100° C. An additional one mL of thesame modifier was added by syringe, and the resulting mixture wasstirred at 100° C. for one hour. The stirring was stopped, the solidswere allowed to settle and the supernate was removed by filtration.Toluene was added and the slurry was stirred at 90° C. for 0.5 h. Thesolids were allowed to settle filtered and toluene (125 mL) and TiCl₄(105 mL) were added, and the mixture was stirred at 90° C. for 0.5 h.The resulting solid was then washed with five 100 mL portions ofheptane. The solids were slurried in heptane (100 mL), transferred to aglove box, filtered on a sintered glass frit, and dried with a stream ofnitrogen, resulting in a fine, pale green powder (approximately 12 g).The solid contained, by weight: 4.09% Ti, 20.2% Mg, content byInductively-Coupled Plasma (ICP). The powder had a uniform particleshape as judged by microscopy and a uniform distribution, d₁₀=12.05,d₅₀=28.82, d₉₀=57.28 microns and span=1.57 as measured by a MalvemMastersizer™ laser diffraction particle size analyzer. This Catalyst A1was used in Examples 4 and 5.

Catalyst Preparation Procedure B:

Preparation of Stripped Support. A Magnesium Chloride-THF AdductCatalyst support as described above (22.5 g) was suspended in heptaneand transferred under nitrogen to a 1-liter jacketed glass reactorfitted with an overhead stirrer. The heptane was removed by decantation,and washed with toluene for one minute with stirring, the solidsrecovered by decantation, and more toluene (125 mL) and titaniumtetrachloride (105 mL, Akzo) were added with stirring. The reactorcontents were warmed to 95° C. and mixed for an additional 1.25 hour,the stirring was stopped, and the solids were allowed to settle. Thesupernate was decanted, and the remaining solids were slurried intoluene (125 mL). The stirring was stopped, the solids were allowed tosettle, and the supernate was removed by filtration. The solids wereslurried in heptane (100 mL), transferred to a glove box, filtered on asintered glass frit, and dried with a stream of nitrogen. A bright pinksolid (12.0 g) was isolated. The solid contained, by weight, 3.2% Ti,18.0% Mg, and 5.35% THF.

Activation of Stripped Support. Catalyst B1. A disposable 30 mL vial wascharged with the stripped support prepared above (0.10 g, 0.74 mmol Mg),toluene (2 mL), donor modifier M2 (15 mg), and TiCl₄ (1 mL). The vialwas placed in a rack, which was set on top of a heating block and heatedto 95 C for 15 min with intermittent agitation. The solids were allowedto settle and the supernate was removed. Toluene (2 mL) and TiCl₄ (0.5mL) was added, and the mixture heated again to 95° C. for 10 min. Afterallowing the solids to settle, the supernate was removed, and theresidue was washed while still warm with toluene (2 mL), followed bythree washes with hexane (2 mL each). The vial was set on its side todry to constant weight in the dry box atmosphere and then capped untilused for polymerization.

Catalyst B2. Procedure B, above, was used, but using 20 mg of modifierM1 and 0.25 mL of TiCl₄.

Catalyst B3. Procedure B was used, but in the first TiCl₄ treatment, nomodifier was used and the mixture was heated to 60° C. for one hour, andin the second TiCl₄ treatment, 10 mg of modifier M1 was used and themixture was heated to 80. C for one hour.

Comparative Catalyst Y1. Procedure B, above, was employed, but nomodifier was used in the preparation.

Comparative Catalyst Y2. Procedure B, above, was employed, but modifierdi-n-butyl phthalate (M2) (15 mg) was used in the TiC₁₋₄-treatments.

Catalysts used in Examples 5-8 and Comparative Runs B and C wereprepared using similar procedures and are further described in Table 1.

Propylene Polymerizations.

Condition A: Standard 2 L, Heptane Slurry. A standard propylenepolymerization is conducted using catalyst A1 in a nitrogen purgedjacketed 2-liter stainless steel Parr reactor fitted with overheadstirrer, flush-bottomed dump valve, and equipped with temperaturecontrol. To the reactor is added 2.0 mL of a 1.25 M heptane solution oftriethylaluminum, 2.0 mL of a 0.125 M heptane solution ofdiisobutyldimethoxysilane, 20 mg of catalyst, and 850 mL of heptane. Theslurry is stirred at 500 rpm at 38° C. Hydrogen (9 mmol) was added,followed immediately by 30 g of liquid propylene. The reactor is warmedand the pressure was increased to 560 kPa with propylene when thetemperature reached 71° C. (after about 15 min). The reactor ismaintained at 71° C., 560 kPa, and 500 rpm for 60 min. The propylenesupply is then turned off and the reactor vented over five minutes untilthe pressure was about 85 kPa. The reactor is pressurized to 305 kPawith nitrogen and then vented twice to remove residual propylene. Thereactor is again pressurized to 305 kPa with nitrogen and the reactorslurry transferred through the bottom dump valve into a filter sock. Theheptane-wet solid obtained in the filter sock is transferred to a glassdish and the solid is dried in a vacuum oven for one hour at 82° C. at0.15 bar with slight purge of nitrogen, and white polypropylene powderis obtained.

Condition B: 300 cc Parr, Bulk Propylene. Polymerization Example 1.Propylene polymerization was conducted in a nitrogen purged jacketed 300mL stainless steel Parr reactor fitted with overhead stirrer andequipped with temperature control. The reactor was brought to about 55°C. and charged with 1.0 mL of a 0.75 M heptane solution oftriethylaluminum, 1.0 mL of a 0.1 M heptane solution ofdiisobutyldimethoxysilane, catalyst B2 (7.3 mg), liquid propylene(approximately 200 mL) and hydrogen (5.7 mmol). The reactor was broughtto 71° C. while stirring at 500 rpm. After 60 min, the temperaturecontrol was shut off, the propylene was slowly vented, and the reactorwas back-filled twice with nitrogen. The polymer was removed from thereactor and air-dried overnight. White polypropylene powder (33 g) wasobtained.

Ex. 2 Condition B was employed, but Catalyst B2 (4.7 mg) was substitutedfor Catalyst B1, 9 mmol of hydrogen were used, and 40 grams of whitepolypropylene powder were obtained.

Ex. 3. Condition B was employed, but substituting Catalyst B3 (6 mg) forCatalyst B1, 6.5 mmol of hydrogen were used, and 39 grams of whitepolypropylene powder were obtained.

Ex. 4. Condition B was employed, but Catalyst A1 (6.1 mg) wassubstituted for Catalyst B1, and 24 grams of very sticky polypropylenepowder were obtained.

Ex. 5. Condition B was employed, but Catalyst A1 (8.9 mg) wassubstituted for Catalyst B1, and 52 grams of white polypropylene powderwere obtained.

Comparative Run A. Condition B was employed, but Comparative Catalyst Y1(3 mg) was substituted for catalyst B1, and only 0.25 mL of thediisobutyldimethoxysilane solution was used, and 74 grams of very stickypolypropylene were obtained.

Comparative Run B. Condition B was used, but Comparative Catalyst Y2 (3mg) was substituted for catalyst B1; 0.25 mL ofdiisobutyldimethoxysilane solution, 11 mmol of hydrogen was used; andthe polymerization time was 72 minutes, and 65 grams of polypropylenepowder were obtained.

Table 2 summarizes the polymerization and polymer properties.

TABLE 2 Polymerization Catalyst Preparation Yield MFR Bulk XyleneHeptane Ex. Ti Mg (gPP/g (g/10 Density Sol. Extrac. (Run) CatalystModifer* (wt %) (wt %) Condition cat) min) (g/cc) (wt. %) (wt. %) 1 B1M1 n.d. n.d. B 5600 6.7 n.d. 13.6 n.d. 2 B2 M1 n.d. n.d. B 8500 4.2 n.d.n.d. n.d. 3* B3 M1 n.d. n.d. B 6500 3.5 n.d. 15.6 n.d. 4 A1 M1 n.d. n.d.B 3900 1.3 n.d. n.d. 14.8 5 A1 M1 n.d. n.d. B 5800 n.d. n.d. n.d. n.d.(A) Y1 (none) n.d. n.d. B 24700 10.0 n.d. 38.6 49.2 (B) Y2 M2 n.d. n.d.B 18100 9.4 n.d.  6.4  8.4 *M1 = Ethyl (phenloxy)acetate M2 = Di-n-butylphthalate n.d. = not determined

“Yield” (grams of polymer produced per gram of solid catalyst component)is de based on the weight of solid catalyst-used to produce polymer.“Solubles” are determined by evaporating the solvent from an aliquot offiltrate to recover the amount of soluble polymer produced and arereported as the weight percent (% Sol.) of such soluble polymer based onthe sum of the weights of the solid polymer isolated by filtration andof the soluble polymer. “Xylene Solubles” (“XS”) are Solubles usingboiling xylenes as the solvent. “Extractables” are determined bymeasuring the loss in weight of a dry sample of ground polymer afterbeing extracted in boiling n-heptane for three to six hours and arereported as the weight percent (% Ext.) of the solid polymer removed bythe extraction. The bulk density (BD) is reported in units of grams percubic centimeter (g/cc). The viscosity of the solid polymer was measuredaccording to ASTM D1238 Condition L (2.16 kg@230° C.) and reported asthe melt flow rate (MFR) in grams of polymer per 10 minutes.

Decalin Solubles (“DS”) is a measure of hydrocarbon soluble andextractable materials, such as atactic, non-crystalline, and oligomericcomponents, contained in a propylene polymer and is useful incorrelating a particular resin to desirable resin properties such asprocessing window. DS is determined by completely dissolving a 2.0-gramsample of polymer in 100 milliliters of Irganox 1076-stabilized (0.020grams/liter) decalin (decahydronaphthalene) by warming the slurry to165° C. and stirring the slurry for two hours. Once the polymer isdissolved, the solution is allowed to cool overnight (at least 16hours). After the cooling period, the solution is filtered from theprecipitated polymer. A measured portion of the solution is withdrawnand, after removing the decalin solvent, the resulting samples arecompletely dried in a 120° C. vacuum oven. The final dried samples areweighed to determine the amount of decalin-soluble polymer. Results arereported as a weight percent polymer remaining soluble in decalin.

1. A process to polymerize propylene or a mixture of propylene andethylene or a C4-C6 alpha-olefin, wherein the improvement comprisesusing a catalyst system containing a solid, hydrocarbon-insoluble,catalyst component useful in polymerizing olefins containing magnesium,titanium, and halogen and further containing an internal electron donorcomprising ethyl (phenylacetoxy) acetate.